Feed mechanism for sewing machines



April 16, 1940. 5 uc 2,197,255

FEED MECHANISM FOR SEWING MACHINES Filed. Sept. 11, 1936 3 Sheets-Sheet 1 F. A. KUCERA 219K255 FEED MEGHANISM FOR SEWING MACHINES Filed Sept. 11, 1936 3 Sheets-Sheet 2 OOO W1 TNESSES:. I N VEN TOR:

' Fhmk flliiwerw; A I W A TORNE-YS.

Patented Apr. 16, 1940 UNITED STATES FEED MECHANISM roa snwmo. mamas Frank A. Kncera, Chicago, Ill.,

aslignor to Union Special Machine Company, Chicago, 11]., a corporation of Illinois Application September 11, 1936, Serial No. 100,259

14 Claims.

This invention relates to feeding mechanism for sewing machines; and it has reference more particularly to feeding mechanism for that type of sewing machine wherein a presser bar is conflned to vertical movement in a needle arm which overhangs a work support whereon the fabric being seamed is advanced to the stitch-forming instrumentalities of the machine.

My. invention is directed toward the provision 10 of a simple andreliable feed mechanism wherein a feed element in the form of a wheel, and an associated presser foot are supported at the lower end of the presser bar in adjacent relation in the line of feeding in such manner as to be capable 1 of yielding independently as irregularities in the fabric pass beneath them on the work support.

In connection with feed mechanism character-' ized as above, I aim to provide flexible actuating means whereby the feed roller is positively and g uniformly rotated intermittently notwithstanding its up and down movements in compensating for variations in the fabric thickness.

Another object of my invention is to secure the foregoing advantages in a feeding mechanism 2 which can be used in an auxiliary capacity with 35 appear from the detailed description, of the attached drawings, wherein Fig. I shows the rear elevation of a sewing machine conveniently embodying the feed mechanism of my invention, portions of the frame of the machine being broken out to expose important details which would otherwise be hidden.

Fig. II shows the elevation of the forward end of the machine with portions of the frame removed and others broken out, likewise to expose 45 important details.

Fig. III is a fragmentary detail section view drawn to a larger scale and taken .as indicated by the arrows IIIIII in Fig. I.

Fig. IV is a fragmentary detail plan sectional so view taken as indicated by the arrows IV-IV in Fig. III; and

Fig. V is a fragmentary detail view taken as indicated by the arrows VV in Fig. III.

The frame of the sewing machine herein illusa trated has a hollow base I, providing a horizontal (Cl. I12-214) work support la which is overhung by a hollow arm 2 extending longitudinal of the machine from a hollow standard 3 at one end of said base. Guided for axial reciprocation in a head 4 at the free end of the overhanging arm 2 above a throat plate 5 secured to the work support la is a vertical bar 6 (see Fig. II) carrying a pair of sewing needles I at its lower end. The needle bar 6 is actuated, through suitable interposed connections (not shown) within the head 4, the arm 2 and the standard 3, by a crank 8 on a longitudinal drive shaft 9 suitably journalled within the hollow base I of the machine frame. Disposed rearwardly of the needle bar 6 (as considered with regard to the direction of feeding which is indicated by the arrows in Figs. 11 and III), and confined to axial movement in the head 4, is the presser bar ID of the machine. By means of a flat adjustable leaf spring ll supported on the top of the arm 2 with its free end bearing on a stirrup l2 engaged over the upper endof the presser bar I ll, said bar is yieldingly urged downwardly toward the work support la.

The feeding mechanism with which the present invention is more especially concerned, comprises a toothed wheel l3 which is journalled within a yoke I4 at the bottom of the presser bar Ill for free rotation about a transverse axis pin it. As shown, the yoke I4 is rigidly secured to the feed bar it) by a pair of set screws I6, and said bar held against rotation through engagement of the downward and outward projection ll of a collar l8 thereon with a vertical slot l9 at one side of said head, see Figs. I and II. As shown in Figs. IV andV, the feed wheel l3 has hollows 20, 2| at opposite sides thereof for accommodating the parts of a roller clutch means whereby it is inter- -mittently rotated to progress the fabric F (Fig. III) along the work support Ia of the-machine. The clutch means just referred to includes a notched cam disk 22 which 23 to one side of the yoke l4 and wherewith cooperate a pair of spring urged rollers 25 within the hollow 20. Occupying the hollow 2| at the other side of the feed wheel I3 is a reversely.

notched cam disk 26 wherewith cooperate a pair 'of spring urged rollers 21, said disk 26 being secured by screws 28 to the fulcrum boss 29 of an upwardly-projecting, laterally-offset actuating arm 30 which engages the pin IS in an interval between thewheel at the corresponding side and the contiguous side of the yoke end, the actuating arm 30 is coupled, by means of a link 3|, with the lower end of a pendant arm 32 affixed to the forward end of a rock shaft 33 is secured by screws,

At its upperwhich extends longitudinally of the rear side of the needle arm 2, as shown in. Figs. I and II, and which is journalled in suitably spaced bearings 34, 35 secured by screws 38, 31 to said needle arm. To the opposite end of the rock shaft 33 is afllxed an arm 38 which extends inwardly through an' opening 39 in the corresponding side of the standard 3 and which is connected by means of a vertical eccentric rod within said standard, with a crank I on the drive shaft 9 immediately adjacent the crank 8 hereinbefore mentioned. As the actuating arm 30 moves clockwise in Fig. III, the rollers 21 are wedged between the sloping edges of the notches in the cam disk25 and the inner periphery of the wheel I! within the hollow 2|, and said wheel thereby given a rotary shift to advance the fabric F. On the other hand, when the actuating arm 30 is swung in the opposite direction, easement of the rollers 21 takes place, while the feed wheel I3 is held against rotation through wedging action of the other set of rollers 25 between the inclined edges of the notches in the disk 22 and the inner periphery of said feed wheel within the hollow 20. In order that the amount of movement thus imparted to the wheel l3 may be regulated, the pendant arm 32 on the rock shaft 33 is constructed with two parts 32a and 32b, the first of which has a longiudinal slot 42 and the other of which carries a clamp screw 43 which is adjustable along said slot. For the protection of the operator of the machine, the feed wheel I! is covered by a guard 44 suitably attached to the top of the yoke H as shown.

Associated withthe feed wheel 13 and located ahead of it in the direction of feeding (indicated by the arrows in Figs. II and IV) is a presser foot l5 which is formed with a flat portion 45a to bear upon the top of the fabric F and with an upwardly inclined frontal deflecting portion 4517, said presser foot having elongated apertures 48 to clear the needles 1. Substantially centrally of the length of its horizontal portion 45a, the presser foot I5 is provided at opposite sides with integral upstanding ears 1 which are pivotally connected, by means of screws 48, to the forward extremities of an H-shaped link member 49 whereof the rear extremities are fulcrumed by screws 50 to the opposite sides of the yoke it, see Figs. DI and IV. Finger springs 5| with coiled portions 52 surrounding anchorage screws 53 at opposite sides of the yoke ll bear upon the forward extremities of the link member 49, with their ends engaging grooves 54 in said extermities so as to be thereby held against lateral displacement. By virtue of the construction just described, .the presser foot 45 is accorded the capacity to move bodily up and down independently of the feed wheel l3 in facilitating passage of fabric irregularities beneath it, as well as to swing or rock independently about its pivotal connections with the link member, which latter movement is yieldingly resisted by a finger spring 55 (Figs. III and IV) which is secured by a screw 56 to one side of the link member 49, and which has its free end retroverted as at 51 and bearing on the flat top of one of the ears For the purpose of limiting the downward movement of the presser foot when the presser bar in is elevated to lift the feed wheel l3 clear of the work support la, there is provided a ver tical keeper link 58 whereof the lower end is pivotally connected to a central lug 59 on the transverse bar 49a (Fig. IV) of the link member 48, and whereof the upper end is longitudinally slotted as at II in Fig. III, for passage of the. shank of a headed screw stud projection 5| on the collar portion Ila of the yoke ll. As shown the slot 50 in the link 58 is of such length as to normally permit the independent up and down and rocking movement of the presser foot 45; but as the presser bar 10 is raised as aforesaid to lift the feed wheel clear of the work support la, the upper edge of said slot will engage the stud projection SI and thereby limit the downward movement of the link member. Thus,

as elevation of the presser bar continues, the

presser footwill in turn be lifted clear of the work support I a; and, conversely, will be the first to contact with said work support when the presser bar I0 is subsequently lowered.

The feed mechanism of my invention may be used alone} or it may be employed in an auxiliary capacity to the usual four motion feed dog 52 (Figs. II and IV) of the sewing machine, when the character of the fabric makes this desirable. It is to be particularly noted that the feed dog 62 coacts through openings 53 in the throat plate 5 directly with presser foot 45 only; and moreover, that feed wheel I 3 engages that portion of the fabric F on the throat plate 5 beyond said presser foot and rearward of the latter in the line of feed. The actuating mechanism for the feed dog 62 is generally designated by the numeral 64 in Fig. II, and lies beneath the work support la, and may be of a type which derives its movements from the drive shaft 9. It is, of course, to be understood that in practice, the parts are so adjusted that the rotary shifts of the feed wheel I3 are synchronized and made to correspond exactly in extent with the active or feed movements of the feed dog 62 to prevent either stretching or crowding of the fabric between the two.

Having thus described my invention, I claim:

1. Feeding mechanism for sewing machines comprising a presser bar confined to axial movement above the work support of the sewing machine; a feed wheel rotatable about an axis carried by the presser bar for vertical movement directly with said bar; means for rotating the wheel to progress fabric along the work support relative to the stitch-forming instrumentalities of the machine; a horizontal link member pivoted for up and down movement on the presser bar; a presser foot attached to the link with capacity for independent pivotal movement; and means for yieldingly maintaining the presser foot in engagement with the fabric.

2. Feeding mechanism for sewing machines comprising a presser bar confined to axial movement above the work support of the sewing machine; a feed wheel carried by the presser bar; means for rotating the wheel to progress fabric along the work support relative to the stitch-forming instrumentalities of the machine; a horizontal link member pivoted for up and down movement on the presser bar; a presser foot attached to the link with capacity for independent pivotal movement; means for yieldingly maintaining the presser foot in engagement with the fabric; and means for yieldingly resisting the independent pivotal movement of said presser foot.

3. Feeding mechanism for sewing machines comprising a presser bar confined to axial movement above the work support of the sewing machine; a feed wheel rotatable about an axis fixed on the presser bar rearward of the needle of the machine in the line of feeding for vertical move a1er,aument directly with said bar; and an associated presser foot ahead of the feed wheel in the line of feeding and pivoted to the presser bar with capacity for movement independently of said bar and said wheel to compensate for irregularities in the fabric being seamed in the machine.

4. Feeding mechanism for sewing machines comprising a presser bar confined to axial movement above the work support of the sewing machine; a feed wheel rotatable about an axis carried by the presser bar for vertical movement directly with said bar; means for rotating the wheel to progress fabric along the work support relative to the stitch-forming instrumentalities of the machine; a presser foot in the line of feed ahead of the wheel; a horizontal link member pivoted at one end to the presser bar and having the presser foot pivotally connected there to at the other end whereby said presser foot is accorded the capacity to move up and down independently of the wheel and to pivot anguiarly as the fabric passes beneath it; and means for yieldingly maintaining the presser foot in engagement with the fabric.

5. Feeding mechanism for sewing machines comprising a presser bar confined to axial movement above the work support of the machine; a bearing yoke secured in fixed relation to the bottom of the presser bar for vertical movement directly with said bar; a feed wheel journaled in said yoke; means for rotating the wheel to progress fabric along the work support relative to the stitch-forming instrumentalities of the machine; a presser foot adjacent the feed wheel; a horizontal link fulcrumed at one end to the yoke and at the other end affording pivotal connection for the presser foot so that the latter is accorded the capacity for up and down movement bodily as well as independent angular pivotal movement incident to the passage of the fabric therebeneath; and a finger spring on the yoke serving to maintain the presser foot in yielding engagement with the fabric.

6. Feed mechanism for sewing machines comprising a presser bar confined to axial movement above the work support of the sewing machine; a bearing yoke secured in fixed relation to the bottom of the presser bar for vertical movement with said bar; a feed wheel journaled in said yoke; means for rotating the wheel to progress fabric along the work support relative to the stitchforming instrumentalities of the machine; a presser foot adjacent the feed wheel; a horizontal link, fulcrumed at one end to the yoke aforesaid and at the other end aflording pivotal connection for the presser foot so that the latter is accorded the capacity for bodily up and down movement as well as independent angular pivotal movement incident to the passage of the fabric therebeneath; and a finger spring on the yoke with its free end bearing downwardly upon the link member to yieldingly maintain the presser foot in engagement with the fabric.

'7. Feed mechanism for sewing machines comprising a presser bar confined to axial movement latter is accorded the capacity for bodily up and down movement as well as independent angular pivotal movement incident to the passage of the fabric therebeneath; a finger spring on the yoke for maintaining the presser foot yieldingly in engagement with'the fabric; and keeper means for limiting the downward movement of the presser foot relative to the feed wheel when the presser bar is actuated to lift said wheel clear of the work support. 1

8. Feed mechanism for sewing machines comprising a presser bar confined to axial movement above the work support of the sewing machine; a yoke at the bottom of the presser bar, said yoke having a projection; a feed wheel journaled in said yoke; means for rotating the wheel to progress fabric along the work support relative to the stitch-forming instrumentalities of the machine; a presser foot adjacent the feed wheel; a horizontal link fulcrumed at one end to the yoke and at-the other end affording pivotal connection for the presser foot so that the latter is accorded capacity for bodily up and down movement 'as well as independent angular pivotal movement incident to the passage of the fabric therebeneath; a finger spring on the, yoke with its free "'end bearing downwardly upon the link member to yieldingly maintain the presser foot in engagement with the fabric; and a slotted vertical keeper link connected to the link member aforesaid and adapted to cooperate with the projection on the yoke to limit the downward movement of said -link member when the presser bar is elevated to lift the wheel clear of the work support.

9. Feed mechanism for sewing machines comprising a presser bar confined to axial movement above the work support of the sewing machine:

a feed wheel journaled at the bottom end of the presser bar and adapted to react upon the work support in feeding fabric on the latter; clutch means within the feed wheel; a presser also connected to the presser bar with capacity to move upwardly independently of the wheel; and means for actuating the clutch means to intermittently rotate the wheel and thereby effect intermittent advance of fabric by the latter on the work support relative to the stitch-forming instrumentalities of the machine.

10. Feed mechanism for sewing machines having a needle arm above a work support, comprising a presser bar confined to axial movement in said arm; a feed wheel journaled at the lower end of the presser bar; a clutch incorporated with the wheel and having an actuating arm; and means forswinging the arm to effect intermittent advance of-fabric by the wheel on the work support relative to the stitch-forming instrumentalities of the machine, including a rock shaft journaled on the needle arm aforesaid, an arm on the rock shaft, and linkage connections between the last mentioned arm and the clutch-actuating arm.

ll. Feed mechanism for sewing machines having a needle arm above a work support, comprising a presser bar confined to axial movement in said arm; a feed wheel journaled at the lower end of the-presser bar; a clutch incorporated with the wheel and having an actuating arm; means for swinging the arm to effect intermittent advance of the fabric by the wheel on the work support relativeto the stitch-forming instrumentalities of the machine, including a rock shaft journaled on the needle arm aforesaid, an arm on the rock shaft, linkage connections between the II last mentioned arm and the clutch-actuating arm, and means whereby the movement imparted to the wheel at each actuation can be ad- Justed.

12. The combination in a sewing machine having a work support with an overhanging needle arm, and a longitudinal drive shaft beneath the work support, of feeding mechanism comprising a presser bar confined to axial movement in the needle arm; a feed wheel carried at the bottom of the presser bar; clutch means associated with the wheel; and means for actuating the clutch means to intermittently rotate the feed wheel and thereby efiect advancement of fabric on the work support relative to the stitch-forming instrumentalities of the machine, including a rock shaft journaled longitudinally of the needle arm, operating connections between the drive shaft and the rock shaft, and linkage connections between said rock shaft and the clutch means.

13. The combination in a sewing machine having a work support, a feed dog beneath said work support, and a presser bar confined to axial movement above the work support, of auxiliary feeding mechanism comprising a feed wheel journaled on an axis at the bottom of the presser bar in the line of feeding rearward of the feed dog for vertical movement directly with said bar; an associated presser foot cooperating with the feed dog above the work support; and a link having one end pivotally connected to the presser bar and affording at its other end a pivotal connection for the presser foot whereby the latter is accorded capacity for up and down movement relative to the feed wheel as well as independent angular pivotal movement.

14. Feed mechanism for sewing machines having a needle arm above the work support, comprising a presser bar confined to endwise movement in said arm; a feed wheel at the lower end of the presser bar; a rock shaft journaled on the overhanging arm; and means extending from said rock shaft to the wheel; means at the wheel operated by the first mentioned means for converting the oscillatory movements of the rock shaft into intermittent rotary feed movements of said wheel for progression of the fabric on the work support relative to the stitch forming elements of the machine.

FRANK A. KUCERA. 

